Element Formerly Known as Eka-Caesium
Puzzle 3 of Periodic Table Medium Pack
Question is: Element Formerly Known as Eka-Caesium
and the answer is: FRANCIUM
Word Meaning:
FRANCIUM — The chemical element (symbol Fr) with an atomic number of 87. It is an intensely radioactive alkali metal that is not found in nature.
Definitions from Wiktionary.